Modify B16.5 flange to B16.36 orifice flange

[PAN]

I can find the related thread.

ANSI 16.5 VS ANSI 16.36
thread174-170011

However, it cannot directly reply to my specific questions.

Flange is A182-F321 size 24" Welding Neck Class 300 per ASME B16.5. If the end user requires to drill hole as per dimension in ASME B16.36. It seems that flange thickness "C" is the same for B16.5 and B16.36

- What should be the major concern especially for QA/QC procedure?
- Do we need any back up calculation to support this modification?

Please comment.

 

[gr2vessels]

If you can drill correctly those holes and you have adequate inspection/testing facility to prove conformity to the B16.36 geometry, all you need is signed and dated ITP's, no additional calculations are required.
cheers,
gr2vessels

 

[JLSeagull]

Aside from verifying that you can modify the ASME B 16.5 flange to an orifice flange, recognize that 24 NPS is a REALLY big orifice flange. Perhaps suggest another flow measurement technology for consideration too.

 

[doct9960]

PAN,

I would be more concerned with liability issues if the flange fails. Check with a B16.36 flange manufacturer if the modification can be done. The manufacturer has the right tools and quality system program set in place.

Please advise us of the outcome.

 

[PAN]

Thanks for all comments. I will try to order orifice flange per ASME B16.36. The field modification from B16.5 to B16.36 will be my last choice, in case of delay delivery.

JLSeagull,
The specific purpose for this orifice flange is for low point drain only. Therefore, I do not worry about flow measurement.

doct9960,
I will try to contact the manufacturers. However, I'm not sure that they will share their know how or manufacturing technology.